Intracranial Glioma Research Articles

Life-style and metabolic factors do not affect risk for glioma: a prospective population-based study (The Cohort of Norway)

BackgroundThe identification of modifiable risk factors for intracranial glioma remains a significant challenge. While lifestyle factors and metabolic syndrome are well-established risk factors for various other cancers, their association with glioma risk remains unclear.ObjectivesThis study aims to conduct a comprehensive analysis of lifestyle factors and metabolic factors in relation to glioma risk.MethodsThe Cohort of Norway (CONOR) is a prospective, population-based health survey encompassing anthropometric measurements, blood tests and health questionnaires. CONOR data were linked to the National Cancer Registry to identify incident glioma cases. Follow-up time was calculated in person-years from the baseline examination until the date of glioma diagnosis, death, or the end of the follow-up period. Cox proportional hazards regression was used to calculate hazard ratios (HR).ResultsThe study cohort included 160,938 women and men. Over 2.8 million person-years of follow-up, 319 intracranial gliomas were diagnosed. Lifestyle factors such as physical activity, alcohol consumption, smoking, and marital status were not associated with glioma risk. There was no increased glioma risk among participants with diabetes mellitus or hypertension. Furthermore, metabolic syndrome in both women and men was not associated with an elevated risk of glioma. Blood lipids, including total cholesterol, triglycerides, and HDL, were not linked to glioma risk. However, increasing LDL levels were associated with a decreased risk of glioma in men (HR per category 0.84; 95% CI 0.74-0.96), but not in women.ConclusionThis is the first comprehensive prospective cohort study to evaluate potentially modifiable risk factors for glioma. Our findings do not support previously suggested associations between smoking, alcohol consumption, or metabolic syndrome and glioma risk.

COL8A1 overexpression promotes glioma cell growth by activating focal adhesion kinase signaling cascade

We explored expression and biological roles of collagen type VIII alpha-1 chain (COL8A1) in glioma. Bioinformatics analyses unveiled COL8A1 overexpression within glioma tissues correlates with adverse clinical outcomes of patients. COL8A1 overexpression was also detected in local glioma tissues and various glioma cells. In primary and immortalized glioma cells, COL8A1 shRNA or knockout (KO) reduced cell viability, proliferation and mobility, disrupted cell cycle, and prompted apoptosis. While COL8A1 overexpression augmented the malignant behaviors in glioma cells. COL8A1 shRNA or KO in primary glioma cells decreased phosphorylation of FAK and downstream targets Akt and Erk1/2. Conversely, elevating COL8A1 expression increased their phosphorylations. In vivo experiments confirmed growth inhibition of patient-derived glioma xenografts within the mouse brain following COL8A1 KO. Hindered proliferation, lowered phosphorylation levels of FAK, Akt, and Erk1/2, as well as increased apoptosis were observed within the COL8A1 KO intracranial glioma xenografts. Thus, COL8A1 overexpression promotes glioma cell growth.

EXTH-69. DEVELOPMENT OF A NOVEL, HUMAN ANTIBODY TO IMPROVE ONCOLYTIC VIRUS THERAPY FOR GLIOBLASTOMA

Abstract Glioblastoma (GBM) is the most aggressive, malignant, primary brain tumor with abysmal overall survival. GBM is regarded as an “immune cold” tumor due to poor immune cell infiltration and immunosuppressive signaling in the tumor microenvironment (TME). Oncolytic herpes virus (oHSV) therapy has emerged as a possible therapeutic avenue for solid tumors such as GBM. We have observed that oHSV-treated tumor cells release extracellular ATP (eATP) which functions as immunostimulatory signaling molecule. In the TME, eATP is rapidly hydrolyzed into immunosuppressive adenosine by ectoenzymes CD39 and CD73. Using global CD73 knock out (CD73KO) mice or a function-blocking murine antibody, we found that blocking CD73 activity improves oHSV therapy in vivo. Intracranial tumor-bearing CD73KO mice respond significantly better to oHSV therapy than wild type (WT). These long-term survivors also rejected a subsequent tumor challenge, demonstrating development of a memory response. scRNA-seq revealed significantly increased immune cell infiltration in CD73KO mice compared to WT. We evaluated cellular crosstalk using CellChat and uncovered a major CCL-directed signaling pathway in the CD73KO mice. Furthermore, we identified a novel, human CD73 antibody from panning an scFv phage display library derived from human tonsils. This antibody, Ab6, demonstrated functional inhibition of purified CD73 and very high binding affinity for CD73. Co-culture of human GBM cells treated with OV and Ab6 and donor PBMCs resulted in increased tumor cell death. Additionally, human DCs exposed to Ab6 and OV-treated conditioned media were better able to activate T cells. To evaluate in vivo efficacy of this novel antibody, we have generated custom humanized CD73 knock-in mice wherein human CD73 has replaced murine CD73. We are currently evaluating the efficacy of Ab6 and oHSV in these mice against intracranial glioma. These results will support the translation of Ab6 as a potential immune therapeutic to add to the arsenal against brain tumors.

EXTH-55. ANTI-TUMOR ACTIVITY OF A NEW ONCOLYTIC ADENOVIRUS DELTA-24-RGDOX-IL15 CO-EXPRESSING OX40L AND IL-15

Abstract Accumulating evidence show that the interaction between oncolytic viruses (OVs) and host immune system plays an essential role in cancer virotherapy. Compared to lytic potency of OVs, enhancement of OV-mediated anti-tumor immunity has become a more attractive strategy to improve OV efficacy. To this end, we have reported that the third-generation oncolytic adenovirus (OA), Delta-24-RGDOX, which expresses the immune co-stimulator OX40 ligand (OX40L), is more potent to elicit anti-tumor immunity than the second-generation OA Delta-24-RGD. Since IL-15 activates T and NK cells and promotes persistence of CD8+ memory T cells, we hypothesize that co-expression of OX40L and IL-15 by OAs will further potentiate their efficacy. For this purpose, we constructed the next generation OA Delta-24-RGDOX-IL15. In cultured human and murine tumor cell lines, this new virus effectively expressed the two molecules and displayed comparable potency in viral replication and oncolysis as OAs expressing either of the two (Delta-24-RGDOX, Delta-24-RGD-IL15). Then, we tested the anti-tumor activity of Delta-24-RGDOX-IL15 (two doses, intratumorally, one week interval) in two syngeneic tumor models in C57BL/6 mice: 1) intracranial (i.c.) gliomas from GL261-5 cells; 2) subcutaneous (s.c.)/i.c. melanomas from B16 cells (virus injected into s.c. tumors only). We found Delta-24-RGDOX-IL15 was more efficacious than the other two OAs to inhibit tumor growth of both treated tumor and the untreated i.c. tumors in the second model, leading to long-term survivors (p < 0.05). Different from adoptive cell therapies with cells engineered to express IL-15, we haven’t observed any obvious toxicity with this new virus when it was injected intratumorally into either the i.c. or s.c. tumors. Further studies are in progress to analyze the modifications of the tumor microenvironment induced by the addition of IL-15 to Delta-24-RGDOX. We expect this virus to be a good candidate to be combined with CAR T cell therapies.

BIOM-52. THE DYNAMIC GLIOMA CSF PROTEOME: IMPACT OF LOCATION AND RESECTION FOR DISEASE MONITORING

Abstract While serial sampling of glioma tissue is rarely performed before recurrence, cerebrospinal fluid (CSF) can be acquired serially to evaluate candidate monitoring and pharmacodynamic biomarkers in patients with gliomas. However, the impact of key variables to consider in longitudinal CSF, including anatomical location and post-surgical changes, remains unknown. To that end, pre- versus post-resection intracranial CSF samples from patients with gliomas were obtained at early (1-16 days; n=20) or delayed (86-153 days; n=11) timepoints, as well as lumbar-versus-intracranial glioma CSF samples (n=14). Using aptamer-based proteomics, we identified significant differences in the glioma CSF proteome between lumbar, subarachnoid, and ventricular CSF. Indeed, intracranial CSF in paired lumbar/intracranial samples had nearly 1600 unique aptamers, regardless of which intracranial location was compared to the paired lumbar CSF, including in enrichment style analyses that evaluated the overlap between protein states. Importantly, resection had a significant, evolving longitudinal impact on the CSF proteome, with subsets of proteins associated with early versus delayed post-resection changes, many of which were enriched for inflammatory-related pathways. Interestingly, despite increased contamination from surgical debris, enrichment for plasma-associated proteins decreased with resection (FDR: 0.000), suggesting that a portion of the baseline glioma panel could be derived from plasma-originating analytes due to blood-brain barrier disruption. Despite these challenges, our data still revealed preliminary candidate monitoring biomarkers, such as brevican, that increased with progression (example patient: fold-change of 3.58x and 2.08x through lomustine and bevacizumab, respectively), but not pseudoprogression (Fold change less than 1.5). Serial intracranial CSF samples suggested the early potential for disease monitoring and evaluation of pharmacodynamic impact of targeted therapies, including bevacizumab and pembrolizumab. In conclusion, our available data to date suggest that the intracranial glioma CSF proteome provides an abundant and evolving source of candidate biomarkers to longitudinally discern the impact of resection and systemic treatments.

TMIC-40. TARGETING GLIOMA TUMOR MICROENVIRONMENT BY SPECIFIC NEUTRALIZATION OF EXTRACELLULAR NICOTINAMIDE PHOSPHORIBOSYLTRANSFERASE (ENAMPT) USING ALT-100, A NOVEL HUMANIZED MONOCLONAL ANTIBODY

Abstract BACKGROUND Intracellular nicotinamide phosphoribosyltransferase (iNAMPT is the rate-limiting enzyme of NAD salvage pathway and is preferentially used by glioma cells for regulating energy metabolism and homeostasis. When secreted, extracellular NAMPT (eNAMPT) exerts cytokine-like functions and is associated with poor prognosis in cancer patients. We have previously reported an essential role of iNAMPT for glioma cell proliferation and survival. Here, we examined whether eNAMPT influences glioma biology and tumor microenvironment by neutralizing eNAMPT using ALT-100, a novel humanized monoclonal antibody. METHODS Native levels of eNAMPT in blood samples of patients with primary/recurrent gliomas were determined using ELISA under an IRB approved protocol. Next, the effects of ALT-100 on glioma microenvironment were determined by treating viable human glioma tissue slices with ALT-100 and assessing downstream effects on RNA and protein using RNASeq, reverse phase protein array and spatial transcriptomics. Lastly, the in vivo effect of ALT-100-mediated eNAMPT neutralization on survival was determined in a mouse intracranial glioma model. RESULTS Measurable levels of eNAMPT were noted in all patient samples with a range of (3.7-71.2 ng/ml). Preliminary results showed a correlation of eNAMPT levels with grade of tumor. Human organotypic glioma slice cultures treated with ALT-100, showed a profound alteration of gene and protein expression particularly related to key energy metabolism and proliferation pathways and the PD-1/PD-L1 axis. Additionally, results of spatial profiling of ALT-100 treated human organotypic glioma slices will be presented. Survival and response data from ALT-100 treatment in ongoing in vivo experiment will also be reported. CONCLUSIONS This is the first report of ALT-100-mediated eNAMPT neutralization in gliomas and demonstrates profound effects on the tumor and its microenvironment. Given that ALT-100 is in phase 2 trials (NCT05938036) against ARDS, data from our studies can potentially accelerate translating ALT-100-mediated eNAMPT neutralization to treat gliomas.

Development of a murine laser interstitial thermotherapy system.

The objective of this study was to develop a murine system for the delivery of laser interstitial thermotherapy (LITT) with probe-based thermometry as a model for human glioblastoma treatment to investigate thermal diffusion in heterogeneous brain tissue. First, the tissue heating properties were characterized using a diode-pumped solid-state near-infrared laser in a homogeneous tissue model. The laser was adapted for use with a repurposed stereotactic surgery frame utilizing a micro laser probe and Hamilton syringe. The authors designed and manufactured a stereotactic frame attachment to work as a temperature probe stabilizer. Application of this novel design was used as a precise method for real-time thermometry at known distances from the thermal ablative center mass during murine LITT studies. Temperature measurements were achieved during LITT that verified the direct thermometry capability of the system without the need for MR-based thermal monitoring. Application of multiple stereotactic design iterations led to an accurately reproducible surgical laser ablation procedure. Histological staining confirmed precise thermal ablation and controllable lesion size based on time and temperature control. Treatment of a syngeneic intracranial glioma model highly resistant to conventional therapy resulted in a modest survival benefit. The authors have successfully developed a murine model system of LITT with direct in situ thermometry for investigation into the effects of thermal ablation and combinatorial treatments in murine brain tumor models.

The peritumoral edema index and related mechanisms influence the prognosis of GBM patients.

Peritumoral brain edema (PTBE) represents a characteristic phenotype of intracranial gliomas. However, there is a lack of consensus regarding the prognosis and mechanism of PTBE. In this study, clinical imaging data, along with publicly available imaging data, were utilized to assess the prognosis of PTBE in glioblastoma (GBM) patients, and the associated mechanisms were preliminarily analyzed. We investigated relevant imaging features, including edema, in GBM patients using ITK-SNAP imaging segmentation software. Risk factors affecting progression-free survival (PFS) and overall survival (OS) were assessed using a Cox proportional hazard regression model. In addition, the impact of PTBE on PFS and OS was analyzed in clinical GBM patients using the Kaplan-Meier survival analysis method, and the results further validated by combining data from The Cancer Imaging Archive (TCIA) and The Cancer Genome Atlas (TCGA). Finally, functional enrichment analysis based on TCIA and TCGA datasets identified several pathways potentially involved in the mechanism of edema formation. This study included a total of 32 clinical GBM patients and 132 GBM patients from public databases. Univariate and multivariate analyses indicated that age and edema index (EI) are independent risk factors for PFS, but not for OS. Kaplan-Meier curves revealed consistent survival analysis results between IE groups among both clinical patients and TCIA and TCGA patients, suggesting a significant effect of PTBE on PFS but not on OS. Furthermore, functional enrichment analysis predicted the involvement of several pathways related mainly to cellular bioenergetics and vasculogenic processes in the mechanism of PTBE formation. While these novel results warrant confirmation in a larger patient cohort, they support good prognostic value for PTBE assessment in GBM. Our results indicate that a low EI positively impacts disease control in GBM patients, but this does not entirely translate into an improvement in OS. Multiple genes, signaling pathways, and biological processes may contribute to the formation of peritumoral edema in GBM through cytotoxic and vascular mechanisms.

Application of 3D-Slicer Software in the Treatment of Gliomas.

To explore the application of 3D-Slicer multimodal image fusion technology in the surgical treatment of gliomas. A retrospective analysis of clinical data from 48 cases of intracranial gliomas treated with 3D-Slicer multimodal image fusion technology from September 2021 to February 2023. Preoperative cranial CT, MRI, TOF-MRA, DTI, and MRV sequence examinations were completed. DICOM format medical imaging data were processed using the 3D-Slicer software. Multimodal fusion and 3-dimensional reconstruction of the tumor and surrounding structures were conducted to clarify the relationship between the tumor and surrounding structures. The surgery path was simulated through 3D virtual visualization images, enabling precise preoperative planning and assisting in surgical treatment. Out of 48 patients, complete tumor resection was achieved in 45 cases. One case encountered severe postoperative cerebral edema, no infections were reported, 1 patient had slightly reduced muscle strength after surgery compared with before, and no cases of severe neurological function damage or surgical death were recorded. 3D-Slicer multimodal image fusion technology can assist in detailed preoperative planning for the surgical treatment of intracranial glioma, reducing surgical complications, improving the rate of total tumor resection, and reducing postoperative complications.

AP-2α decreases TMZ resistance of recurrent GBM by downregulating MGMT expression and improving DNA damage

AimsThe incidence of recurrent gliomas is high, exerting low survival rates and poor prognoses. Transcription factor AP-2α has been reported to regulate the progression of primary glioblastoma (GBM). However, the function of AP-2α in recurrent gliomas is largely unclear. MethodsThe expression of AP-2α and O6-methylguanine DNA-methyltransferase (MGMT) was detected in recurrent glioma tissues and cell lines by Western blots, the regulation mechanisms between AP-2α/MGMT promoter and RA/AP-2α promoter were studied by luciferase reporter assays, EMSA, and chIP assays. The effects of AP-2α and TMZ/RA treatment on cell viability in vitro and in vivo were investigated by MTT assays, γH2AX staining, comet assays and intracranial injection. Key findingsAP-2α expression negatively correlates with the expression of MGMT in glioma samples. AP-2α could directly bind with the promoter of the MGMT gene, suppresses transcriptional levels of MGMT and downregulate MGMT expression in TMZ-resistant U87MG-R and T98G cells, but TMZ treatment decreases AP-2α expression and increases MGMT expression. The extended TMZ treatment and increased TMZ concentrations reversed these effects. Moreover, AP-2α overexpression combines with TMZ to decrease cell viability, concurrently with improved DNA damage marker γH2AX. Furthermore, retinoic acid (RA) activates RAR/RXR heterodimers, which bind to RA-responsive elements (RAREs) of the AP-2α promoter, and activates AP-2α expression in recurrent glioma cells. Finally, in intracranial relapsed glioma mouse model, both RA and TMZ could retard tumor development and prolong the mouse survival. SignificanceAP-2α activation by gene overexpression or RA treatment reveals the suppressive effects on glioma relapse, providing a novel therapeutic strategy against malignant refractory gliomas.

Mitogen-activated protein kinase kinase kinase 1 facilitates the temozolomide resistance and migration of GBM via the MEK/ERK signalling.

Mitogen-Activated Protein Kinase Kinase Kinase 1 (MAP3K1) is overexpressed in gliomas; however, its clinical significance, biological functions, and underlying molecular mechanisms remain unclear. Abnormal overexpression of MAP3K1 in glioma is strongly associated with unfavourable clinicopathological characteristics and disease progression. MAP3K1 could potentially serve as a reliable diagnostic and prognostic biomarker for glioma. MAP3K1 silencing suppressed the migration but had no effect on the proliferation and cell death of Glioblastoma Multiforme (GBM) cells. MAP3K1 knockdown exacerbated the temozolomide (TMZ) induced inhibition of glioma cell proliferation and death of GBM cells. In addition, MAP3K1 knockdown combined with TMZ treatment significantly inhibited the growth and increased cell death in organoids derived from GBM patients. MAP3K1 knockdown reversed TMZ resistance of GBM in intracranial glioma model. In terms of molecular mechanisms, the phosphorylation level of ERK was significantly decreased by MAP3K1 silencing. No significant change in the JNK pathway was found in MAP3K1-silenced GBM cells. Inhibition of ERK phosphorylation suppressed the migration and enhanced the TMZ sensibility of GBM cells. MAP3K1 was correlated with the immune infiltration in glioma. MAP3K1 could facilitate the migration and TMZ resistance of GBM cells through MEK/ERK signalling.

Combination of microRNA and suicide gene for targeting Glioblastoma: Inducing apoptosis and significantly suppressing tumor growth in vivo

Glioblastoma (GBM), a grade IV brain tumor, presents a severe challenge in treatment and eradication due to its high genetic variability and the existence of stem-like cells with self-renewal potential. Conventional therapies fall short of preventing recurrence and fail to extend the median survival of patients significantly. However, the emergence of gene therapy, which has recently obtained significant clinical outcomes, brings hope. It has the potential to be a suitable strategy for the treatment of GBM. Notably, microRNAs (miRNAs) have been noticed as critical players in the development and progress of GBM. The combined usage of hsa-miR-34a and Cytosine Deaminase (CD) suicide gene and 5-fluorocytosine (5FC) prodrug caused cytotoxicity against U87MG Glioma cells in vitro. The apoptosis and cell cycle arrest rates were measured by flow cytometry. The lentiviral vector generated overexpression of CD/miR-34a in the presence of 5FC significantly promoted apoptosis and caused cell cycle arrest in U87MG cells. The expression level of the BCL2, SOX2, and P53 genes, target genes of hsa-miR-34a, was examined by quantitative real-time PCR. The treatment led to a substantial downregulation of Bcl2 and SOX2 genes while elevating the expression levels of Caspase7 and P53 genes compared to the scrambled control. The hsa-miR-34a hindered the proliferation of GBM cancer cells and elevated apoptosis through the P53–miR-34a–Bcl2 axis. The CD suicide gene with 5FC treatment demonstrated similar results to miR-34a in the apoptosis, cell cycle, and real-time assays. The combination of CD and miR-34a produced a synergistic effect. In vivo, anti-GBM efficacy evaluation in rats bearing intracranial C6 Glioma cells revealed a remarkable induction of apoptosis and a significant inhibition of tumor growth compared with the scrambled control. The simultaneous use of CD/miR-34a with 5FC almost entirely suppressed tumor growth in rat models. The combined application of hsa-miR-34a and CD suicide gene against GBM tumors led to significant induction of apoptosis in U87MG cells and a considerable reduction in tumor growth in vivo.

Chrysomycin A Reshapes Metabolism and Increases Oxidative Stress to Hinder Glioblastoma Progression.

Glioblastoma represents the predominant and a highly aggressive primary neoplasm of the central nervous system that has an abnormal metabolism. Our previous study showed that chrysomycin A (Chr-A) curbed glioblastoma progression in vitro and in vivo. However, whether Chr-A could inhibit orthotopic glioblastoma and how it reshapes metabolism are still unclear. In this study, Chr-A markedly suppressed the development of intracranial U87 gliomas. The results from airflow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) indicated that Chr-A improved the abnormal metabolism of mice with glioblastoma. Key enzymes including glutaminase (GLS), glutamate dehydrogenases 1 (GDH1), hexokinase 2 (HK2) and glucose-6-phosphate dehydrogenase (G6PD) were regulated by Chr-A. Chr-A further altered the level of nicotinamide adenine dinucleotide phosphate (NADPH), thus causing oxidative stress with the downregulation of Nrf-2 to inhibit glioblastoma. Our study offers a novel perspective for comprehending the anti-glioma mechanism of Chr-A, highlighting its potential as a promising chemotherapeutic agent for glioblastoma.

NRBP1 promotes malignant phenotypes of glioblastoma by regulating PI3K/Akt activation.

Glioblastoma (GBM) is the most aggressive of intracranial gliomas. Despite the maximal treatment intervention, the median survival rate is still about 14-16 months. Nuclear receptor-binding protein 1 (NRBP1) has a potential growth-promoting role on biology function of cells. In this study, we investigated whether NRBP1 promotes GBM malignant phenotypes and the potential mechanisms. The correlation between NRBP1 and glioma grade, prognosis in TCGA/CGGA databases and our clinical data were analyzed. Next, we conducted knockout and overexpression of NRBP1 on GBM cells to verify that NRBP1 promoted cell proliferation, invasion, and migration invitro and invivo. Finally, we detected the impact of NRBP1 on PI3K/Akt signaling pathway and EMT. There was a correlation between elevated NRBP1 expression and advanced stage glioma, as well as decreased overall and disease-free survival. The suppression of proliferation, invasion, and migration of tumor cells was observed upon NRBP1 knockout, and invitro studies also demonstrated the induction of apoptotic cell death. Whereas, its overexpression is associated with high multiplication rate, migration, invasion, and apoptotic escape. GO enrichment and KEGG analysis revealed that NRBP1 regulated differentially expressed gene clusters are involved in PI3K/Akt signaling pathway, as well as EMT mediated by this pathway. Moreover, the effects of NRBP1 knockdown and overexpression on GBM were mitigated by MK-2206 and SC79, both of which respectively function as an inhibitor and an activator of the PI3K/Akt signaling pathway. Similarly, the suppression of NRBP1 led to a decrease in tumor growth, whereas its overexpression promoted tumor growth in a mouse model. This study shows that NRBP1 promotes malignant phenotypes in GBM by activating PI3K/Akt pathway. Hence, it can function as both a predictive indicator and a new target for therapies in GBM treatment.

Origin recognition complex 6 overexpression promotes growth of glioma cells

The discovery of novel oncotargets for glioma is of immense significance. We here explored the expression patterns, biological functions, and underlying mechanisms associated with ORC6 (origin recognition complex 6) in glioma. Through the bioinformatics analyses, we found a significant increase in ORC6 expression within human glioma tissues, correlating with poorer overall survival, higher tumor grade, and wild-type isocitrate dehydrogenase status. Additionally, ORC6 overexpression is detected in glioma tissues obtained from locally-treated patients and across various primary/established glioma cells. Further bioinformatics scrutiny revealed that genes co-expressed with ORC6 are enriched in multiple signaling cascades linked to cancer. In primary and immortalized (A172) glioma cells, depleting ORC6 using specific shRNA or Cas9-sgRNA knockout (KO) significantly decreased cell viability and proliferation, disrupted cell cycle progression and mobility, and triggered apoptosis. Conversely, enhancing ORC6 expression via a lentiviral construct augmented malignant behaviors in human glioma cells. ORC6 emerged as a crucial regulator for the expression of key oncogenic genes, including Cyclin A2, Cyclin B2, and DNA topoisomerase II (TOP2A), within glioma cells. Silencing or KO of ORC6 reduced the mRNA and protein levels of these genes, while overexpression of ORC6 increased their expression in primary glioma cells. Bioinformatics analyses further identified RBPJ as a potential transcription factor of ORC6. RBPJ shRNA decreased ORC6 expression in primary glioma cells, while its overexpression increased it. Additionally, significantly enhanced binding between the RBPJ protein and the proposed ORC6 promoter region was detected in glioma tissues and cells. In vivo experiments demonstrated a significant reduction in the growth of patient-derived glioma xenografts in the mouse brain subsequent to ORC6 KO. ORC6 depletion, inhibited proliferation, decreased expression of Cyclin A2/B2/TOP2A, and increased apoptosis were detected within these ORC6 KO intracranial glioma xenografts. Altogether, RBPJ-driven ORC6 overexpression promotes glioma cell growth, underscoring its significance as a promising therapeutic target.

LGG-16. BRAFV600K LOW-GRADE GLIOMA EMERGENCE DURING THERAPY FOR BRAFV600E HIGH-GRADE GLIOMA

Abstract BACKGROUND BRAFV600E mutations are prevalent in pediatric brain tumors, constituting 20% of low-grade and 5% of high-grade gliomas. Other single-nucleotide substitutions in BRAF are described in adult cancers but rarely in pediatric brain tumors. Our case sheds light on a unique scenario—a patient with a BRAF-mutated high-grade spinal glioma who later developed slowly progressive intracranial low-grade glioma, subsequently undergoing rapid high-grade transformation. METHODS Case Report RESULTS Our patient initially presented as a thirteen-year-old male with a two-month history of progressive bilateral hand weakness/paresthesias. Spine MRI revealed a fusiform expansile intramedullary neoplasm from C3-T2, brain MRI was negative. Biopsy showed an anaplastic astrocytoma with BRAFV600E mutation and MYC-N amplification. Initial treatment included proton radiation and a 2-year course of Dabrafenib/Trametinib, maintaining disease stability. After four months off therapy, he developed local progression, and re-staging brain MRI showed new cerebellar/supratentorial lesions. Dabrafenib/Trametinib was re-started until progression two years later. He developed hydrocephalus and underwent ETV and brain tumor biopsy, which revealed a low-grade glioma with BRAFV600K mutation. At this point, Dabrafenib/Trametinib continued for another 1.5 years; he exhibited slow progression of the brain tumors before a cerebellar lesion developed rapid progression. He had GTR of the rapid-growing lesion, and pathology reported a Grade 4 invasive astrocytoma harboring BRAFV600E, two VUS MTOR mutations, and MGMT promoter methylation. Current treatment involves radiation therapy concurrent with temozolomide. CONCLUSIONS While combinatorial Dabrafenib/Trametinib is effective in glioma therapy, resistance and progression challenges persist. Our case presents a unique manifestation—a patient with a spinal high-grade glioma with BRAFV600E who developed a secondary low-grade glioma with BRAFV600K in the brain, which, after several years, transformed into a high-grade glioma. Future research is crucial for comprehending the intricate role of BRAF mutations in pediatric gliomas, paving the way for improved patient outcomes.

SMYD2 induced PGC1α methylation promotes stemness maintenance of glioblastoma stem cells.

The high fatality rate of glioblastoma (GBM) is attributed to glioblastoma stem cells (GSCs), which exhibit heterogeneity and therapeutic resistance. Metabolic plasticity of mitochondria is the hallmark of GSCs. Targeting mitochondrial biogenesis of GSCs is crucial for improving clinical prognosis in GBM patients. SMYD2-induced PGC1α methylation and followed nuclear export are confirmed by co-immunoprecipitation, cellular fractionation, and immunofluorescence. The effects of SMYD2/PGC1α/CRM1 axis on GSCs mitochondrial biogenesis are validated by oxygen consumption rate, ECAR, and intracranial glioma model. PGC1α methylation causes the disabled mitochondrial function to maintain the stemness, thereby enhancing the radio-resistance of GSCs. SMYD2 drives PGC1α K224 methylation (K224me), which is essential for promoting the stem-like characteristics of GSCs. PGC1α K224me is preferred binding with CRM1, accelerating PGC1α nuclear export and subsequent dysfunction. Targeting PGC1α methylation exhibits significant radiotherapeutic efficacy and prolongs patient survival. These findings unveil a novel regulatory pathway involving mitochondria that govern stemness in GSCs, thereby emphasizing promising therapeutic strategies targeting PGC1α and mitochondria for the treatment of GBM.

Use of complementary therapies and supportive measures of patients with intracranial gliomas—a prospective evaluation in an outpatient clinic

PurposePatients with intracranial gliomas frequently seek for complementary and alternative medicine (CAM), in addition to guideline-directed therapy. In this study, we therefore assessed patients’ information needs regarding treatment and support, and evaluated their attitudes toward experimental trials and alternative therapies.MethodsA prospective, cross-sectional, descriptive survey was conducted in our center. We developed an interview focusing on how patients obtain further information about therapy and the use of alternative/complementary therapies.ResultsA total of 102 patients participated in the survey. 50% (n = 51) of patients reported that they had not attempted any additional therapies. When patients attempted self-therapy, it was most commonly in the areas of nutrition (25%, n = 26) and dietary supplements (17%, n = 17). Alternative or complementary therapies were used by 14% (n = 14) of the patients. Younger age (Odds ratio (OR) 0.96 (95% Confidence interval (CI) 0.92–0.99, p = 0.012) and tumor entity (OR 5.01 (95% CI 1.66–15.11, p = 0.004) for grade 4 vs. 3 tumors and OR 7.22 (95% CI 1.99–26.28) for grade 4 vs. other tumors p = 0.003) were significantly associated with a greater interest in CAM.ConclusionsInterest in complementary and alternative medicine, as well as nutrition and dietary supplements is high (51%) among glioma patients, and significantly higher among younger patients and those with a worse diagnosis (WHO grade 4). A comprehensive approach to information, including paramedical topics, is needed to provide optimal patient counseling and care for glioma patients.

High PGC-1α Expression as a Poor Prognostic Indicator in Intracranial Glioma.

Gliomas are the most common primary brain tumors in adults. Despite multidisciplinary treatment approaches, the survival rates for patients with malignant glioma have only improved marginally, and few prognostic biomarkers have been identified. Peroxisome proliferator-activated receptor γ (PPARγ) coactivator-1α (PGC-1α) is a crucial regulator of cancer metabolism, playing a vital role in cancer cell adaptation to fluctuating energy demands. In this study, the clinicopathological roles of PGC-1α in gliomas were evaluated. Employing immunohistochemistry, cell culture, siRNA transfection, cell viability assays, western blot analyses, and in vitro and in vivo invasion and migration assays, we explored the functions of PGC-1α in glioma progression. High PGC-1α expression was significantly associated with an advanced pathological stage in patients with glioma and with poorer overall survival. The downregulation of PGC-1α inhibited glioma cell proliferation, invasion, and migration and altered the expression of oncogenic markers. These results conclusively demonstrated that PGC-1α plays a critical role in maintaining the malignant phenotype of glioma cells and indicated that targeting PGC-1α could be an effective strategy to curb glioma progression and improve patient survival outcomes.

Dual-modified brain-targeting lipid polymer micelle delivery of anti-miRNA-21 for achieving oral treatment of glioma

Glioma represents a predominant intracranial malignancy, with fewer than 40 % of patients surviving beyond five years. MiRNA-21 antisense oligonucleotides (anti-miR-21) hold considerable promise for managing aggressive intracranial gliomas. Yet, challenges such as in vivo degradation, suboptimal brain targeting, and inadequate tumor penetration compromise the therapeutic efficacy of unmodified miRNA-21 inhibitors. To overcome these obstacles, we designed an orally-administered, brain-targeted anti-miRNA-21 lipid polymer micelle system (BTMLPMS), dually modified with Ang-2 and TAT. This modification ensures the stable delivery of anti-miR-21, leveraging the protective capacities of lipid polymer micelles to effectively impede glioma growth in vivo. In vitro studies confirmed that these micelles were efficiently uptaken by glioma cells, resulting in induced apoptosis. Importantly, in an orthotopic glioma xenograft model using nude mice, oral administration of these micelles activated pro-apoptotic proteins p53 and Caspase-3, effectively inducing apoptosis in tumor tissues and curbing tumor progression. Hematoxylin-eosin staining further validated the biocompatibility of the micelles. Collectively, our findings underscore the potential of the anti-miR-21 lipid polymer micelle system as a significant advancement in glioma gene therapy, paving the way for groundbreaking transformations in miRNA clinical applications.